Straightening apparatus

ABSTRACT

A straightening apparatus includes a primary plate, a movable plate, upper and lower pressing wheels and a guiding wheel. The movable plate is movable relative to the primary plate between an open position and a closed position. The upper pressing wheels are connected to the movable plate. The lower pressing wheels are connected to the primary plate. The guiding wheel is connected to the primary plate. The upper pressing wheels are located closer to the lower pressing wheels in the closed position than the open position. The tube can be located between the upper and lower pressing wheels in the open position. The upper and lower wheels together provide a straightening passage for straightening the tube in the closed position. The tube is pressed by the guiding wheel before the tube is straightened in the straightening passage.

BACKGROUND OF INVENTION 1. Field of Invention

The present invention relates to a straightening apparatus and, more particularly, to an apparatus for straightening pipes of various sizes.

2. Related Prior Art

Taiwanese Patent M352409 discloses a machine for straightening recycled iron bars. The straightening machine includes a first set of inlet wheels, a second set of inlet wheels, a set of straightening wheels, a set of outlet wheels, a frame for supporting the sets of wheels, and a motor for driving the sets of wheels via a transmission. In use, the first set of inlet wheels and the second set of inlet wheels move the recycled iron bars to the set of straightening wheels. The set of straightening wheels presses and hence straightens the recycled iron bars while moving them to the set of outlet wheels. Then, the set of outlet wheels moves the recycled iron bars out of the straightening machine. The straightening machine is suitable for straightening relatively thick iron bars in a factory. However, the straightening machine hence is not portable for being bulky and heavy. Hence, the straightening machine is not suitable for straightening relatively thin iron bars on field.

U.S. Pat. No. 4,116,037 discloses a hand-held straightening apparatus including two levers 12 and 16, two jaws 14 and 20 respectively connected to the levers 12 and 16, and a linkage 18 for connecting the lever 12 to the lever 16. The jaw 14 includes a semi-cylindrical groove 30. The jaw 20 includes a semi-cylindrical groove 34. The semi-cylindrical grooves 30 and 34 together provide a cylindrical channel when the jaws 14 and 20 are in contact with each other. In use, a recycled iron bar is located between the jaws 14 and 20. The levers 12 and 16 are pivoted toward each other to move the jaws 14 and 20 to each other via the linkage 18. Thus, the jaws 14 and 20 press and straighten the recycled iron bar. However, the diameter of the cylindrical channel is constant, and hence the hand-held straightening apparatus is only suitable for straightening recycled iron bars of a single diameter.

The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.

SUMMARY OF INVENTION

It is the primary objective of the present invention to provide a hand-held straightening apparatus suitable for straightening recycled iron bars of various diameters.

To achieve the foregoing objective, the straightening apparatus includes a primary plate, a movable plate, upper pressing wheels, lower pressing wheels and a guiding wheel. The movable plate is movable relative to the primary plate between an open position and a closed position. The upper pressing wheels are connected to the movable plate. The lower pressing wheels are connected to the primary plate. The guiding wheel is connected to the primary plate. The upper pressing wheels are located closer to the lower pressing wheels in the closed position than the open position. The tube can be located between the upper pressing wheels and the lower pressing wheels in the open position. The upper pressing wheels and the lower pressing wheels together provide a straightening passage for straightening the tube in the closed position. The tube is pressed by the guiding wheel before the tube is straightened in the straightening passage.

Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be described via detailed illustration of the preferred embodiment referring to the drawings wherein:

FIG. 1 is an exploded view of a hand-held straightening apparatus according to the first embodiment of the present invention;

FIG. 2 is an exploded view of the hand-held straightening apparatus shown in FIG. 1;

FIG. 3 is a right side view of the hand-held straightening apparatus shown in FIG. 1;

FIG. 4 is a left side view of the hand-held straightening apparatus in another position than shown in FIG. 1;

FIG. 5 is a right side view of the hand-held straightening apparatus in another position than shown in FIG. 3;

FIG. 6 is an enlarged, partial and front view of the hand-held straightening apparatus shown in FIG. 1, used for a first bar;

FIG. 7 is an enlarged, partial and front view of the hand-held straightening apparatus shown in FIG. 1, used for a second bar; and

FIG. 8 is an enlarged, partial and front view of the hand-held straightening apparatus shown in FIG. 1, used for a third bar.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring to FIGS. 1 to 5, a straightening apparatus includes a straightening unit 10 and a handling unit 70 according to the preferred embodiment of the present invention. The handling unit 70 is operable to drive the straightening unit 10 to straighten a tube or bar 52 of stainless steel or copper with diameter of 3/16 to ½ inches for example. The straightening apparatus is operable to straighten a tube or bar 52 without having to use electricity or pressurized air for example.

The handling unit 70 includes two levers 71 and 72 pivotally interconnected by a pin 73 like a pair of scissors for example. Hence, the levers 71 and 72 are pivotable toward and away from each other about the pin 73. The first lever 71 includes two lateral leaves (not numbered). The second lever 72 includes two leaves (not numbered). The leaves of the second lever 72 are located between the leaves of the first lever 71. Referring to FIG. 3, a tab 79 is formed on an internal side of one of the leaves of the second lever 72.

A lock 84 is provided on a side of the handling unit 70. The lock 84 includes a pawl 75, a key 76 and a detent 78. The pawl 75 is formed with teeth 77 and a shoulder 80. The key 76 is formed with a shoulder (not numbered). The pawl 75 is attached to a side of the first lever 71 by several rivets (not numbered). The key 76 is located between and pivotable relative to the pawl 75 and the first lever 71. The detent 78 is pivotally connected to the second lever 72.

The detent 78 is engageable with one of the teeth 77 of the pawl 75, the shoulder of the key 76 and the shoulder 80 of the first lever 71, thereby keeping the levers 71 and 72 closed. The key 76 is operable to disengage the detent 78 from the shoulder of the key 76 and the shoulder 80, thereby allowing the levers 71 and 72 to open. After the key 76 is released, the detent 78 is automatically engaged with the shoulder of the key 76 and the shoulder 80, thereby keeping the levers 71 and 72 at a desired angle relative to each other. More details of the handling unit 70 can be found in U.S. Pat. No. 9,789,615.

The straightening unit 10 includes a primary plate 11, a movable plate 20, a rotatable plate 60 and a wheel set (not numbered). The primary plate 11 includes two limiting slots 12, three vertical slots 13, arched slot 14, a securing aperture 15, apertures 16, and securing apertures 17. The limiting slots 12 extend parallel to each other. The vertical slots 13 extend parallel to one another. The arched slot 14 is located higher than the vertical slots 13.

The movable plate 20 includes a horizontal slot 21, two screw holes 22 and three apertures 23. The horizontal slot 21 is located higher than the apertures 23. The screw holes 22 are located relative to the limiting slots 12. The apertures 23 are located relative to the apertures 16.

The rotatable plate 60 includes a cutout 61 and two apertures 62 and 63. The cutout 61 is made in a rear end of the rotatable plate 60. The aperture 62 is located near the cutout 61. The aperture 63 is located near a front end of the rotatable plate 60.

The pin 73 is inserted in the securing aperture 15. Rivets 74 are inserted in the securing apertures 17. Thus, the primary plate 11 is connected to the first lever 71 so that they are not movable relative to each other. The primary plate 11 and the lock 84 are located on two opposite sides of the first lever 71. Two threaded bolts 30 are inserted in the screw holes 22 of the movable plate 20 through the limiting slots 12 of the primary plate 11 and two washers 36. Thus, the movable plate 20 is movable relative to the primary plate 11 as the threaded bolts 30, which are inserted in the screw holes 22 of the movable plate 20, are movable in and along the limiting slots 12 of the primary plate 11. The movable plate 20 is in contact with and movable relative to the primary plate 11. Hence, lubricating grease or oil can be provided between the movable plate 20 and the primary plate 11 to reduce friction between the movable plate 20 and the primary plate 11 if necessary.

A driving element 34 is inserted in at least one washer 36, the aperture 63 of the rotatable plate 60, the horizontal slot 21 of the movable plate 20 and the arched slot 14 of the primary plate 11 and then engaged with a nut 38. A driving element 34 is preferably a threaded bolt engaged with a nut 38. Thus, the rotatable plate 60, the movable plate 20 and the primary plate 11 are joined together. Now, the arched slot 14 and the horizontal slot 21 intersect, and the driving element 34 is located at the point of intersection.

The rear portion of the rotatable plate 60 is located between the leaves of the second lever 72. The tab 79 is inserted in the cutout 61. The pin 73 is inserted in the aperture 62. Thus, the rotatable plate 60 and the second lever 72 are rotatable together. The rear portion of the plate 60 is located out of the second lever 72 so that the aperture 63 is located out of the second lever 72.

The wheel set includes upper pressing wheels 40, lower pressing wheels 42, a guiding wheel 44 and a lateral wheel 46. An upper plank 50, a lower plank 53 and a supporting element 81 are used to help hold these wheels in position.

There are preferably four upper pressing wheels 40. However, any other proper number of upper pressing wheels 40 can be used. Each of the upper pressing wheels 40 is made centrally with an aperture 41. The upper plank 50 includes fourth apertures 51 evenly made therein. A threaded bolt 401 is inserted in one of the apertures 51 of the upper plank 50 and the aperture 41 of one of the upper pressing wheels 40 and engaged with a nut. Three more threaded bolts 401 are inserted in the remaining the apertures 51 of the upper plank 50, the apertures 23 of the movable plate 20 and the vertical slots 13 of the primary plate 11 and then engaged with nuts 38. The vertical slots 13 are longer than the limiting slots 12, and hence do not interfere with the movement of the upper pressing wheels 40 and the movable plate 20. The upper pressing wheels 40 are located on a side of the upper plank 50 while the movable plate 20 is in contact with another side of the upper plank 50.

There are preferably three lower pressing wheels 42. However, any other proper number of lower pressing wheels 42 can be used. Each of the lower pressing wheels 42 is centrally made with an aperture 43. The lower plank 53 is made with three apertures 54. Three threaded bolts 421 are inserted in the apertures of the lower plank 53 and the apertures 16 of the primary plate 11 and then engaged with three nuts. Thus, the lower pressing wheels 42, the lower plank 53 and the primary plate 11 are interconnected. The lower pressing wheels 42 are located on a side of the lower plank 53 while the primary plate is in contact with another side of the lower plank 53. The lower plank 53 is made with thickness identical to that of the upper plank 50 plus that of the movable plate 20, rendering the lower pressing wheels 42 exactly blow the upper pressing wheels 40.

The lower plank 53 includes a reduced portion 55 at a rear end, a lowered portion 56 at a front end, and two parallel lateral portions 57 between the reduced portion 55 and the lowered portion 56. The reduced portion 55 is made with width smaller than that of the remaining portions of the lower plank 53. The lowered portion 56 extends lower than the remaining portions of the lower plank 53.

The lower plank 53 further includes a recess 561 and two screw holes 562 and 563. The recess 561 is made in a rear end of the lowered portion 56 so that the recess 561 is in communication with a gap between the lateral portions 57. The screw hole 562 horizontally extends throughout the lowered portion 56. The screw hole 563 vertically extends throughout the lowered portion 56.

The fasteners 74 are inserted in two apertures 551 made in the reduced portion 55. Thus, the lower plank 53 is non-movably connected to the first lever 71.

The supporting element 81 is made with a transverse tail 83 so that the supporting element 81 is L-shaped. An aperture 85 is made in a portion of the supporting element 81 from which the tail 83 extends.

A spring 58 is located in the gap between the lateral portions 57 of the lower plank 53. An end of the spring 58 is fitted in the recess 561 so that the spring 58 is connected to the lower plank 53.

The tail 83 is inserted in the gap between the lateral portions 57 of the lower plank 53. A fastener 571 is inserted in an aperture (not numbered) made in each of the lateral portions 57 of the lower plank 53 and the aperture 85 of the supporting element 81, thereby pivotally connecting the supporting element 81 to the lower plank 53. An opposite end of the spring 58 is in contact with the tail 83 so that the spring 58 is compressed between the tail 83 of the supporting element 81 and the lowered portion 56 of the lower plank 53.

A threaded bolt 441 is inserted in a screw hole (not numbered) made in the supporting element 81 through an aperture 45 made in the guiding wheel 44, thereby connecting the guiding wheel 44 to the supporting element 81. An adjusting element 82 in the form of a threaded bolt is inserted throughout the screw hole 563. A tip of the adjusting element 82 is in contact with a lower face of the supporting element 81. Thus, the adjusting element 82 is operable to lift and lower the guiding wheel 44 relative to the lower plank 53.

A threaded bolt 461 is inserted in the screw hole 562 through an aperture (not numbered) made in the lateral wheel 46, thereby rotationally connecting the lateral wheel 46 to the lower plank 53. A bearing 47 is preferably provided between the lateral wheel 46 and the threaded bolt 461 to render rotation of the lateral wheel 46 smooth.

Referring to FIG. 5, in an open position, the rotatable plate 60 moves the driving element 34 toward an upper closed end of the arched slot 14 along the arched slot 14. Synchronously, the rotatable plate 60 moves the driving element 34 toward a rear closed end of the horizontal slot 21 along the horizontal slot 21. Thus, the movable plate 20 is moved rearward and upward relative to the primary plate 11. Accordingly, the upper pressing wheels 40 are moved away from the lower pressing wheels 42.

Referring to FIG. 3, in a closed position, the rotatable plate 60 moves the driving element 34 toward a lower closed end of the arched slot 14 along the arched slot 14. Synchronously, the rotatable plate 60 moves the driving element 34 toward a front closed end of the horizontal slot 21 along the horizontal slot 21. Thus, the movable plate 20 is moved forward and downward relative to the primary plate 11. Hence, the upper pressing wheels 40 are moved toward the lower pressing wheels 42. The upper pressing wheels 40 are located above and close to the wheels. The upper pressing wheels 40 are arranged in an alternate manner with the lower pressing wheels 42. The upper pressing wheels 40 and the lower pressing wheels 42 together provide a straightening passage 48 (FIGS. 6 to 8).

Referring to FIGS. 6 through 8, a tube or bar 52 of any proper diameter is located between the upper pressing wheels 40 and the lower pressing wheels 42 when the straightening unit 10 is in the open position as shown in FIG. 5. The tube or bar 52 is pulled and straightened by the straightening unit 10 as the straightening unit 10 is moved to the closed position as shown in FIG. 3.

The straightening apparatus exhibits several advantages. Firstly, the straightening apparatus is small and easily portable.

Secondly, a user can use the straightening apparatus to straighten the tube or bar 52 that is originally in a roll without having to cut the tube or bar 52. The straightening process can proceed toward the roll.

Thirdly, the upper pressing wheels 40 and the lower pressing wheels 42 are rotatable for 360 degrees about the axis of the tube or bar 52. Thus, the straightening apparatus is operable even in a limited space.

Fourthly, the guiding wheel 44 is located ahead of the straightening passage 48. Hence, the tube or bar 52 is pressed by the guiding wheel 44 before the tube or bar 52 is straightened in the straightening passage 48.

Fifthly, the lateral wheel 46 can be rolled on a table, a floor or a wall to facilitate the tube or bar 52 in various places. However, the straightening apparatus is still workable without the lateral wheel 46.

The present invention has been described via the illustration of the preferred embodiment. Those skilled in the art can derive variations from the preferred embodiment without departing from the scope of the present invention. Therefore, the preferred embodiment shall not limit the scope of the present invention defined in the claims. 

1. A straightening apparatus comprising: a primary plate (11); a movable plate (20) movable relative to the primary plate (11) between an open position and a closed position; upper pressing wheels (40) connected to the movable plate (20); and lower pressing wheels (42) connected to the primary plate (11); wherein the upper pressing wheels (40) are located closer to the lower pressing wheels (42) in the closed position than in the open position; wherein a tube (52) can be located between the upper pressing wheels (40) and the lower pressing wheels (42) in the open position; wherein the upper pressing wheels (40) and the lower pressing wheels (42) together provide a straightening passage (48) for straightening the tube (52) in the closed position.
 2. The straightening apparatus according to claim 2, further comprising: an upper plank (50) located between and connected to the upper pressing wheels (40) and the movable plate (20); and a lower plank (53) located between and connected to the lower pressing wheels (42) and the primary plate (11).
 3. The straightening apparatus according to claim 2, wherein the lower plank (53) is made with width identical to that of the upper plank (50) plus that of the movable plate (20).
 4. The straightening apparatus according to claim 2, further comprising a guiding wheel (44) connected to the primary plate (11), wherein the tube (52) is pressed by the guiding wheel (44) before the tube (52) is straightened in the straightening passage (48).
 5. The straightening apparatus according to claim 4, further comprising a supporting element (81) for pivotally connecting the guiding wheel (44) to the lower plank (53).
 6. The straightening apparatus according to claim 5, further comprising a spring (58) compressed between a portion of the supporting element (81) and a portion of the lower plank (53), thereby biasing another portion of the supporting element (81) toward another portion of the lower plank (53).
 7. The straightening apparatus according to claim 6, further comprising adjusting element (82) connected to the lower plank (53) and abutted against the supporting element (81) so that the adjusting element (82) is operable to move the supporting element (81) away from the lower plank (53) against the spring (58).
 8. The straightening apparatus according to claim 7, wherein the lower plank (53) comprises a lowered portion (56) formed at a front end and two lateral portions (57) extending from the lowered portion (56), wherein the supporting element (81) comprises a tail (83) located between and pivotally connected to the lateral portions (57), wherein the spring (58) is compressed between the tail (83) and the lowered portion (56), wherein the adjusting element (82) is connected to the lowered portion (56).
 9. The straightening apparatus according to claim 8, wherein the tail (83) transversely extends from an end of the supporting element (81).
 10. The straightening apparatus according to claim 8, wherein the adjusting element (82) is a threaded bolt, wherein the lowered portion (56) is made with a screw hole (563) for receiving the adjusting element (82).
 11. The straightening apparatus according to claim 8, further comprising a lateral wheel (46) attached to the lowered portion (56), wherein the lateral wheel (46) and the guiding wheel (44) are located on two opposite sides of the lower plank (53).
 12. The straightening apparatus according to claim 1, further comprising threaded bolts (30) for pivotally connecting the movable plate (20) to the primary plate (11), wherein the movable plate (20) comprises apertures (22) for non-movably receiving the threaded bolts (30), wherein the primary plate (11) comprises limiting slots (12) for movably receiving the threaded bolts (30).
 13. The straightening apparatus according to claim 1, further comprising lubricant provided between the primary plate (11) and the movable plate (20).
 14. The straightening apparatus according to claim 1, further comprising a rotatable plate (60) and a driving element (34) for interconnecting the primary plate (11), the movable plate (20) and the rotatable plate (60).
 15. The straightening apparatus according to claim 14, wherein the primary plate (11) comprises an arched slot (14) for movably receiving the driving element (34), wherein the movable plate (20) comprises a horizontal slot (21) for movably receiving the driving element (34), wherein the rotatable plate (60) comprises an aperture (62) for non-movably receiving the driving element (34).
 16. The straightening apparatus according to claim 15, wherein the arched slot (14) and the horizontal slot (21) intersect, wherein the driving element (34) is located at the point of intersection of the arched slot (14) and horizontal slot (21).
 17. A straightening apparatus comprising: a primary plate (11); a movable plate (20) movable relative to the primary plate (11) between an open position and a closed position; upper pressing wheels (40) connected to the movable plate (20); lower pressing wheels (42) connected to the primary plate (11); and a guiding wheel (44) connected to the primary plate (11); wherein the upper pressing wheels (40) is located closer to the lower pressing wheels (42) in the closed position than the open position; wherein a tube (52) can be located between the upper pressing wheels (40) and the lower pressing wheels (42) in the open position; wherein the upper pressing wheels (40) and the lower pressing wheels (42) together provide a straightening passage (48) for straightening the tube (52) in the closed position; and wherein the tube (52) is pressed by the guiding wheel (44) before the tube (52) is straightened in the straightening passage (48). 